With clutch actuators, accurate determination of the axial position of an actuating unit or the angular position for example of a rotor is necessary. With new designs of such clutch actuators it is now necessary to dispose the sensors used for this at a distance from an axis of rotation. In this case, dynamic tolerances (i.e. differences from an initial position occurring during operation of the clutch actuator) must also be taken into account, for example an eccentricity of individual components and a changing air gap between the first sensor and a permanent magnet that is in use.